Stacker



June 3, 1969 J, D. KREPP ET AL STACKER Sheet Filed Nov. 21, 1966 INVENTORS JOHN 0. 4466A? U6N 4. M4065) AII Q Wan- WM Q

June 3, 1969 J. D. KREPP ET AL STACKER Sheet Filed Nov. 21, 1966 June 3, 1969 J, D. KREPP ET AL STACKER Sheet Filed Nov. 21, 1966 M Arrawvvexs United States Patent O 3,447,695 STACKER John D. Krepp and Eugene L. Mackey. Cleveland, Ohio, assignors, by mesne assignments, to P & F Industries, Inc., Great Neck, N.Y., a corporation of New York Filed Nov. 21, 1966, Ser. No. 595,829 Int. Cl. B65g 57/03; B65h 31/34 US. Cl. 214-6 Claims ABSTRACT OF THE DISCLOSURE The invention relates in general to a stacking or piling mechanism and more particularly to a mechanism to stack or pile pieces coming from a continuous processing line such as from a flying cutoff for sheet metal pieces and the like. The pieces may be flat or may be rolled or formed shapes, for example, corrugated metal roofing and other formed pieces.

The invention may be incorporated in a stacker, comprising, in combination, a fixed frame, a plurality of supports on said frame for supporting pieces to be stacked, said supports each having first and second conditions with said first condition establishing the pieces in a pass plane parallel to said plurality of supports, means to convey the pieces toward the downstream end of the conveying means with said supports in said first condition, said second condition of said supports being a divert condition to divert pieces from said pass plane, stop means facing upstream engageable by the downstream end of the pieces diverted from said conveying means, and means to selectively control said first and second conditions of each of said plurality of supports to selectively divert pieces of variable lengths from said pass plane of said conveying means onto a stack with the downstream end of the pieces adjacent said stop means and the upstream end of the pieces a variable distance from said stop means in accordance with the length of each of the pieces.

In many continuous processing mechanisms, a continuous strip is processed for convenience in handling rather than the slower batch process of a group of individual pieces. Next a flying cutoff is used to cut the continuous strip into pieces of the desired length, and then these cut off pieces must be stacked and removed from the vicinity of the end of the processing line. As continuous processing lines become faster in operation, the stacker must also become faster. Speeds of 300 feet per minute are now becoming common for such things as sheet metal roofing forming line and stacker mechanisms of the prior art have been unable to adequately cope with this higher speed of operation. Further increased flexibility is desired by having the pieces coming off of variable lengths and the stacker should be able to stack pieces of such variable lengths. Many art stackers had the construction wherein the cut off pieces were trapped between first and second stops at each end of the pieces, and when a change in length was desired, it was necessary to shut down the machine or at least to stop the flow of cut off pieces in order to change one of these end stops. This interruption of the entire processing line was highly undesirable.

Accordingly an object of the present invention is to obviate the above mentioned disadvantages.

3,447,695 Patented June 3, 1969 Another object of the invention is to provide a stacker which will stack pieces at high speeds.

Another object of the invention is to provide a stacker which will readily stack pieces of variable lengths.

Another object of the invention is to provide a stacker wherein the length of the stacked pieces may be changed while the pieces are coming oil? a processing line and being stacked.

Another object of the invention is to provide a stacker wherein a stack is controlled or aligned only at the downstream end and the pieces are not trapped between two stops. 7

Another object of the invention is to provide a stacker which may operate at high speed and which permits the pieces to be dropped onto a stack with a minimum of falling leaf floating in the air during dropping.

Another object of the invention is to provide a stacker wherein the pieces are precisely positioned on a stack without the necessity of engaging both ends of the stacked piece.

Another object of the invention is to provide a stacker wherein the pieces are selectively diverted from a pass plane by a changed condition of a plurality of supports by selecting certain ones of the plurality of supports in accordance with the length of the piece being stacked.

Another object of the invention is to provide a stacker with only a single end stop facing upstream.

Another object of the invention is to provide a stacker which may be readily adjusted in vertical position to accommodate pieces of variable thickness.

Another object of the invention is to provide a stacker wherein pieces are supported and conveying means are provided to move the pieces until the desired position is reached for stacking.

Another object of the invention is to provide a stacker wherein different length pieces may be piled on a single stack with the length changing during the run of pieces.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which FIGURE 1 is a side elevational view of a stacker embodying the invention;

FIGURE 2 is an enlarged sectional view of line 2-2 of FIGURE 1;

FIGURE 3 is an enlarged elevational view of part of the'adjustment mechanism of the stacker;

FIGURE 4 is a sectional view on line 44 of FIG- URE 3;

FIGURE 5 is an enlarged plan view of the stop means;

FIGURE 6 is a vertical sectional view of part of the stop means; and,

FIGURE 7 is a diagrammatic view of the program controller for the stacker.

The figures of the drawing show the preferred embodiment of the invention in a stacker 11. This stacker includes a fixed frame '12 and a movable frame 13. The movable frame 13 is carried on the fixed frame 12 by bell crank levers '14 having a pivot 15 on the fixed frame 12. A first arm 16 has an end pivoted to the movable frame 13, and a second arm 17 has an end pivoted to links 18 which interconnects all of the bell crank levers 14. A screw 20 and nut '21 connect the links 18 to the fixed frame at a pivot connection 22. By adjusting the screw 20 and nut 21, the links 18 may be moved forwardly and backwardly to adjust all of the bell crank levers 14 simultaneously. This moves the movable frame 13 up and down for height adjustments, to be later explained.

The stacker 11 stacks pieces 25 coming from a flying cutoff, not shown, along a pass plane 26 by a conveyor 27. As shown in FIGURE 2, the pieces 25 may be corrugated, as one example, so that even though of relatively light gauge sheet metal, the effective thickness of each piece might be one-half inch or up to two inches, for example. This is the necessity for the height adjustment of the movable frame 13 to accommodate the effective thickness of each piece 25.

In the stacker 11 the pieces 25 are supported by a plurality of supports 30. These supports, in this preferred embodiment, are support rollers journalled on the lower ends of arms 31. The plurality of arms are journal-led on shafts 32 for at least partial arcuate movement. The shafts 32 are provided one on each side of the fixed frame 12 and parallel to the pass plane 26 on each side of and above the movable frame 13. The supports 30 have first and second conditions with the first condition being illustrated in solid lines in FIGURE 2. This first condition is one wherein the support rollers 30 are generally horizontal and the axes thereof are perpendicular to the pass line of the pieces 25 in the pass plane '26. This pass line is along the longitudinal length of the stacker 11. This first condition of the plurality of support rollers supports the pieces 25 in this pass plane. The second condition of the supports 30 is shown in phantom lines 30A in FIGURE 2 with these supports positioned laterally to one side of the movable frame 13. This is a release condition to permit the pieces 25 to be diverted from the pass plane, in this case they are permitted to drop by gravity from this pass plane. The second condition shown at 30A of the supports is caused by the arms 31 swinging laterally outwardly on the shafts '32 to move the supports 30 laterally beyond each side of the movable frame 13. Fluid power cylinders 33 are connected between the fixed frame 12 and the arms 31 in order to move the supports 30 between the first and second conditions.

A holding bank 36 also is provided on the shafts 32. This holding bank includes a plurality of arms 37 journalled on the shafts for partial rotation. Pads 38 are carried on the lower ends of the arms 37 and have a first condition, shown in solid lines in FIGURE 2, disposed generally horizontally beneath the movable frame 13. The pads 38 also have a second condition shown in phantom lines 38A disposed to one side of the movable frame 13. The holding bank 36 is provided to temporarily hold pieces 25 when a completed stack 39 is to be moved from underneath the stacker 11, as by the power driven rolls 40. Fluid power cylinders 41 are connected to the arms 37 to move the holding bank between the first and second conditions.

Means is provided to convey the pieces 25 on the plurality of support rollers 30. This conveying means 45 conveys the pieces generally along the pass plane 26. The support rollers 30 in the first condition thereof support the pieces for action by the conveying means 45. The conveying means 45, in this preferred embodiment, is illustrated as carried on the movable frame 13 and is adjustable in height dependent on the thickness of the pieces as mentioned above. The conveying means 45 includes a plurality of rolls 46 and drive means 47. The rolls 46 are accordingly power driven, and the support rollers 30 hold the pieces 25 in frictional engagement with this conveying means 45 to effect the movement of the pieces. All of the rolls 46 are substantially simultaneously power driven by a belt conveyor 48 having upper and lower runs 49 and 50, respectively, and upstream and downstream ends 51 and 52, respectively. The lower surface of the lower run 50 is that which frictionally engages the upper surface of the pieces 25 to convey them downstream along the pass plane 26. The entire belt conveyor 48 may have several sets of three rollers 46, only one set being shown, along the length of the lower run 50 in order to take up the slack and more importantly to break up the lower run 50 into shorter lengths so that the sag of the belt is not appreciable. This is especially important when the arms 31 have moved to the second or release condition to drop a piece 25 and are .4 subsequently returned to the first condition to support the next piece 25 up against the belt conveyor 48.

The drive means 47 includes an electric motor 55 mounted on the fixed frame 12 which drives a speed reducer such as a gear reducer 56 by means of a belt 57. The gear reducer 56 in also mounted on the fixed frame 12 and has an output shaft 58. A drive gear 59 is mounted on this output shaft and meshes with a driven gear 60 on the input shaft 61 of one sheave or end roll 62 for the belt conveyor 48. The distance between the output shaft 58 and input shaft 61 is the same as the length of the tfirst arm 16 of the bell crank levers 14. Accordingly the intermeshing gears 59 and 60 remain enmeshed as the screw and nut means 20 and 21 is adjusted to move all of the bell crank levers 14 and adjust the height of the movable frame 13. The bell crank levers 14 establish the pivotal connection between the output and input shafts 58 and 61 or additionally there may be provided an actual physical pivotal link between these two shafts 58 and 61, although in practice this has not been found necessary. The bell crank levers 14 provide a form of parallelogram connection to maintain the movable frame 13 horizontal, in this case parallel to the pass plane '26 throughout the height adjustment. Also the gears 59 and 60 are accordingly maintained in drive engagement in the drive train during this height adjustment.

FIGURES 1, 3, 5 and 6 show stop means 65 which faces upstream to engage the downstream end 24 of the pieces 25. In this case, the stop means 65 is positioned adjacent the downstream end of the stacker 11 in order to utilize the entire length of the stacker especially for long pieces to be stacked.

In one practical embodiment of the invention, the stacker was capable of stacking pieces up to a maximum of 32 feet long, and of practically any length shorter than such maximum length.

The stop meaans 65 includes first and second portions 66 and 67, respectively. This stop means is better shown in FIGURES 5 and 6 wherein the first portion 66 is generally vertical and faces upstream to engage the downstream end 24 of the pieces 25. The second portion 67 is a shelf which has first and second conditions. The first condition is as shown in FIGURE 6 wherein it is generally horizontal and constitutes a shelf to support the downstream end 24 of the pieces 25. The second condition of the shelf 67 is a position 67A as shown in phantom lines on FIGURE 6 wherein the shelf 67 has been rotated approximately 90 degrees relative to the first portion 66 to drop the downstream end 24 of the pieces onto the stack 39. A rotary fluid motor 68 is connected to move the shelf 67 between the first and second conditions.

The stop means 65 may be mounted on a base 70 which is fixed relative to the fixed frame 12. This stop means 65 is carried on slide rods 71 slidably journalled in bearings 72 to move rearwardly or downstream upon being struck by a piece 25. A shock absorber 73 is mounted between the first portion 66 and the base 70 to absorb the impact from the pieces 25 as they strike the first portion 66. A fiuid cylinder motor 74 may be connected in axial alignment with shock absorber 73 and may have a predetermined stroke, for example, two inches in order to effect a stagger stacking of the stack 39. This stagger stacking is to permit a predetermined number, for example, ten pieces to be stacked in vertical alignment and then the next ten pieces are stacked displaced by a predetermined amount for example, one or two inches. The next group of ten pieces is stacked in alignment with the first group and so on. This helps 'an observer to quickly count the number of pieces in a given stack and also helps separating the stack at a required number of pieces. A fluid cylinder motor 75 is connected between the first portion 66 and the base 70 to slowly return the first portion 66 upstream after it has been pushed downstream by the impact of a piece 25 diverted from the conveying means 45. During the last portion of the upstream return movement, the shelf 67 is swung downwardly to the second position 67A in order to drop the downstream end 24 of the piece into precise alignment with the other pieces on the stack 39.

A lifter 78 may be provided to lift the power driven rollers 40 upwardly, and then to lower these rollers progressively as the stack 39 builds. This maintains the top of the stack closely adjacent below the supports 30 so that the pieces 25 do not have far to fall.

FIGURE 7 diagrammatically illustrates the control mechanism including a program controller. A digital length controller 80 is provided having an input 81 into which digital length information i fed by an operator. This will be information as to the length of each piece to be cut by the flying cutoff, not shown, and to be handled by the stacker 11. Also a quantity batch controller 82 is provided having an input 83 into which an operator supplies information as to the number of pieces in each batch of a predetermined length. The digital length controller 80 has a first output 84 to control the batch controller 82 to correlate the information on the length of each piece in the batch. The digital length controller 80 also has a second output 85 to an end stop deceleration unit 86. This unit 86 also has another input 87 from the batch controller 82. The end stop deceleration unit 86 is connected to control the cylinder 75 effecting upstream return movement of the stop means first portion 66. The end stop deceleration unit 86 has three outputs. One to support arms program unit 88, another to the holding bank program 89 and a third to a stagger stack unit 90. The support arms program unit 88 is connected to control the cylinder 33 moving the support arms 31. The holding bank program unit 89 is connected to control cylinders 41 which move the holding bank 36. The stagger stack unit 90 is connected to control the fluid cylinder 74 which provides stagger stacking in the stack 39.

Operation The stacker 11 may be controlled in a highly automated manner. As an example, if one is stacking pieces of sheet metal coming off the flying cutoff of a continuous processing line, this stacker 11 will stack pieces of various lengths, automatically according to a predetermined program. As an example, let it be assumed that it is desired to cut fifteen pieces 25 each thirty feet in length and stack these and then to immediately change to cutting and stacking twenty additional ten foot long pieces. The length information of thirty feet is supplied on the input 81 to the length controller 80 and then the number of pieces in the batch. namely fifteen, is supplied on the input 83 to the batch controller 82. These inputs may be digital inputs of any form such as punched cards, punched tape or magnetic tape. The length of ten feet for the pieces of the second batch is next supplied to the length controller 80 and the twenty pieces for that batch supplied on the input 83 to the batch controller 82. The holding bank 36 will be in the second position 38A of the pads 38 to be out of the way. The processing line may then he started, and the flying cutoff will be prognammed to cut the required length of pieces. Sensing means, not shown, will sense the length of each piece so that is may be out at the required lenth. The conveyor 27 may be run at a higher speed than the flying cutoff in order to accelerate the pieces and provide a space between each piece 25 as it approaches the stacker 11. Sensing means, not shown, count the number of pieces, and hence this information on length and number of pieces is also fed into the length controller and batch controller 80 and 82, respectively. With the first piece of thirty foot length being supplied to the stacker 11, all of the support rollers 30 will be in the first condition which holds the pieces against the bottom run 50 of the belt conveyor 48. Accordingly, this piece is conveyed the full length of the stacker 11. When the piece has run the full length of the stacker, it will strike the stop means 65. The shock absorber 73 will absorb the impact of the piece 25 and a limit switch 93, shown in FIGURE 7, is actuated by movement of stop means to cause the support arms 31 to he swung outwardly by the fluid cylinders 33. This is under the control of the support arms program unit 88. Accordingly, the support rollers 30 move from the first condition to the second or release condition to permit the piece 25 to drop. The upstream end 23 of the piece 25 will drop to the stack. In this case at the beginning of the stacking the first piece will drop to a pallet support 94 carried on the lifter 78. The downstream end 24 will drop only a short distance to the shelf 67. The support arms 31 having released the piece 25 will next swing back to the first condition to be in a position to receive the next piece coming off the conveyor 27 along the pass plane 26. Meanwhile, the end stop first portion 66 having retracted under the impact of the piece 25, will now be returned slowly upstream by the fluid cylinder 75. During this upstream movement, the downstream end 24 of the piece will be supported on the shelf 67. During the final portion of this upstream movement, the rotary fluid motor 68 will be actuated to drop the shelf 67 and hence drop the downstream end of the piece 25 into precise alignment on the stack 39. The stop means 65 will now be in its initial position ready to receive the downstream end of the next piece coming off the conveying means 45.

After ten pieces have been counted by the batch controller 82, in the above example, the stagger stack cylinder 74 may be actuated to move the stop means 65 upstream the predetermined amount. This may be one or two inches, for example, to stagger the next group of pieces 25. After the number of pieces in the batch have been counted, fifteen pieces in the above example, the batch controller 82 will switch to the next batch. As the ten foot pieces 25 come along the support rollers 30, as moved by the con veying means 45, they also will strike the stop means 65. Now, however, the length controller 80 will control the support arms program unit 88 so that only the last five of the support roller arms 31 are moved outwardly. This is wit-h the assumption that the support rollers are spaced at two foot intervals, and hence the supports next adjacent the stop means 65 are those which are actuated to the second or release condition. This drops only the last piece adjacent the stop means 65 while the support rollers 30, upstream from this ten foot length, remain in their first condition to support pieces 25 being conveyed through the stacker 11.

Again the pieces, of shorter length this time, drop to the stack with the upstream end 23 frictionally engaging the stack and the downstream end 24 supported on the shelf 67 Again the stop means 65 is retracted under the impact and is then moved upstream by the cylinder to precisely position the piece on the stack.

The lifter 78 gradually lowers as the stack builds to maintain the top of the stack 39 closely below the level of the pads 38 of the holding bank 36. When the stack has reached maximum height, then the holding bank program unit 89 is actuated to move the holding bank pads 38 from the second to the first position underneath the conveying means 45. This holding bank 36 permits temporary storage of pieces still coming off the processing line while the power operated rollers 40 move the stack 39 laterally from underneath the stacker 11 to a storage position. The lifter 78 may then lift another pallet support 94 into position beneath the support pads 38 and in fact may actually hit the temporarily held stack off the pads 38 so that the holding bank 36 may be swung outwardly to the second condition 38A. This permits continuous running of the processing line and the stacker 11 so that the entire line need not be shut down merely because one stack 39 is completed.

Only one simple example has been given of only two lengths, but it will be obvious to one skilled in the art that the stacker 11 may be programmed to stack any desired length of pieces and with any number of pieces to a batch and with a different length of pieces in successive batches in any desired order.

Because there is only the single stop means 65 which is near the downstream end, and which faces upstream, there is no need to move any stop means in the stacker 11 in order to change length of pieces. Prior art stackers trapped the pieces between a downstream and an upstream end stop. This meant that it was necessary to shift the lengthwise position of one of these stops in order to change length of pieces being stacked. Whereas the conveying means of the prior art might be left running, this would not mean that pieces could be actually coming off the stacker during this length adjustment. The adjustment usually required unfastening some bolts and physically moving the large end stop to a new position. This took several minutes, and accordingly it was mandatory to stop the pieces coming into the stacker. The present invention obviates such a situation wherein the entire processing line has to be shut down. The pieces being stacked are all physically aligned at the downstream end by the stop means 65, and the upstream end is not engaged by a stop and is a variable distance from the stop means 65. Hence there is no stop means that needs to be moved for length adjustment. The support arms program unit 88 controls a selected number of the support roller arms 31 adjacent to and immediately upstream from the stop means 65 in accordance with the length of the piece being conveyed at that instant to the stack 39. This assures that the following pieces will still be supported by the support rollers 30.

The stacker 11 uses the supports 30 to establish the pieces 25 in the pass plane 26. Means is provided to divert pieces from this pass plane, and in this preferred embodiment such means is the arrangement of the stacker so that the pieces fall by gravity from the pass plane when the support rollers 30 are moved to the second condition 30A. The stop means 65 has the first portion 66 which is disposed generally perpendicular to the pass plane 26 and has the second portion or shelf 67 which is disposed generally parallel to the pass plane 26. As illustrated in FIG- URE 1, after the pieces 25 have fallen, the upstream end 23 will frictionally engage the stack 39 and the downstream end 24 will rest on the shelf 67. This supports the piece 25 at an acute angle to the horizontal. This accomplishes two things. The first is that it eliminates the falling leaf effect of a fiat sheet attempting to fall while in a generally horizontal position. The air beneath it tends to make it move from side to side and along its length and it does not fall directly vertically downwardly. Accordingly, if the pieces were merely allowed to fall, they would not fall directly on the stack 39 into alignment therewith. The second beneficial effect is that the acute angle of the piece 25 means that the upstream end 23 frictionally engages the topmost piece on the stack. Thus as the cylinder motor 75 moves the piece slowly back upstream, the upstream end 23 will stabilize the piece 25 so that it will be precisely aligned into position on the stack 39.

The stop means 65 has the first and second portions 66 and 67, respectively. As the stop means is returned back upstream by the fluid cylinder motor 75, the shelf 67 and the first portion 66 relatively move to permit the downstream end 24 of the piece to drop. In this preferred embodiment the shelf 67 moves downwardly from a generally horizontal position toward a generally vertical position to permit this relative movement.

The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. A stacker, comprising, in combination, a fixed frame,

a plurality of spaced supports on said frame arranged longitudinally along the path of travel of pieces for supporting pieces to be stacked. said supports each having first and second conditions with said first condition establishing the pieces in a pass plane parallel to said plurality of supports,

means to convey the pieces toward the downstream end of the conveying means with said supports in said first condition,

said second condition of said supports being a divert condition to divert pieces from said pass plane,

stop means facing upstream engageable by the downstream end of the pieces diverted from said conveying means,

and means to selectively control said first and second conditions of each support of said plurality of supports to select the second condition of those supports which correspond to the length of the piece to selectively divert pieces of variable lengths from said pass plane of said conveying means onto a stack with the downstream end of the pieces adjacent said stop means and the upstream end of the pieces a variable distance from said stop means in accordance with the length of each of the pieces whereby a stack of different length pieces may be formed.

2. A stacker as set forth in claim 1 wherein said conveying means includes a plurality of rolls with the lower surface thereof disposed generally in said pass plane, and means to substantially simultaneously drive each of said rolls.

3. A stacker as set forth in claim 1 including a movable frame for said conveying means,

connection means to support said movable frame for parallelogram movement relative to said fixed frame for movements of said movable frame transverse to the said pass plane,

drive means on said fixed frame,

and a drive train from said drive means to said conveying means and including a pivotal connection of the same length as said parallelogram connection to maintain said drive train in engagement despite parallelogram adjustment of said conveying means.

4. A stacker as set forth in claim 3 wherein said parallelogram connections include bell crank levers to pivotally support said movable frame relative to said fixed frame,

a link interconnecting all of said bell crank levers for simultaneous parallelogram movement,

and screw and nut means to adjust said link means relative to said fixed frame to adjust the transverse dimension of said conveying means relative to said pass plane.

5. A stacker as set forth in claim 3 including an output shaft on said drive means,

an input shaft on said conveying means,

and means disposing said pivotal connection of said drive train as pivoted on the axes of said output and input shafts to maintain a constant distance therebetween despite pivotal movements of said drive train pivotal connection during transverse adjustments.

6. A stacker as set forth in claim 5 including a drive gear on said output shaft,

a driven gear on said conveyor input shaft,

and said drive and driven gears intermeshing despite changes of arcuate position of said driven gear around said drive gear.

7. A stacker as set forth in claim 1 wherein said control means controls a selected number of said plurality of supports in a group adjacent to and upstream from said stop means, and said selected number of supports having a dimension parallel to said direction of movement of the pieces approximately equal to the length of the piece being conveyed.

8. A stacker asset forth in claim 1 wherein said stop means has first and second portions,

said first portion facing upstream and disposed transversely to said pass plane to be engaged by the downstream end of any of the pieces diverted from said pass plane,

said second portion having a component generally parallel to said pass plane and displaced therefrom to be disposed generally horizontally,

the upstream end of the pieces falling onto a stack upon being diverted from said pass plane,

the downstream end of the pieces being supported on said second portion of said stop means to support the pieces at an angle to the horizontal,

and means to relatively move said first and second portions of said stop means to move a piece upstream toward alignment on the stack of pieces and to terminate the support of the downstream end of the piece on said second portion to permit the downstream end to fall onto the stack in alignment therewith.

9. A stacker as set forth in claim 8 wherein said means to relatively move said first and second portions of said stop means includes means to move said first portion of said stop means slowly upstream to position a piece on the stack of pieces, and means to move said second portion from a generally horizontal position to a generally vertical position to drop the piece.

10. A stacker as set forth in claim 1 wherein said stop means includes an end stop device, and shock absorber means on said stop device to absorb the force of a piece striking said end stop device as it moves downstream and is dropped by said plurality of supports.

11. A stacker as set forth in claim 10 including fluid power means on said end stop device to move same slowly upstream to push pieces upstream to precisely position each of the pieces on a stack with the downstream end of each of the pieces aligned at said end stop device.

12. A stacker as set forth in claim 1 including an end stop device as part of said stop means,

a shelf on said end stop device to support the downstream end of any of said pieces above the stack while permitting the upstream end of any of said pieces to frictionally engage the stack to thus support such pieces at an angle to the horizontal.

power means to move said end stop device upstream to position any of the pieces,

and means to retract said shelf relative to said end stop device to permit the downstream end of any of said pieces to drop onto the stack.

13. A stacker as set forth in claim 12 wherein said power means is fluid power means to move said end stop device slowly upstream to precisely position any of said pieces,

and said shelf being pivoted on said end stop device with first and second positions,

said first position of said shelf being generally horizontal and said second position of said shelf being generally vertically downward,

' means to establish said shelf in said first position to support the downstream end of any of said pieces as said fluid power means moves said pieces slowly upstream,

and means to move said shelf to said second position to drop the downstream end of any said pieces into position on the stack.

14. A stacker as set forth in claim 1, including power means to move said stop means upstream to position each of said pieces on a stack,

a pivoted shelf on said stop means having first and second positions,

said first position of said shelf being generally horizontal and said second position of said shelf being generally vertically downward,

means to establish said shelf in said first position with said power means moving said piece upstream,

and means to move said shelf to said second position to drop the downstream end of said piece into position on the stack.

15. A staoker as set form in claim 1, including program means to selectively control said first and second condition of said plurality of supports.

References Cited UNITED STATES PATENTS 2,456,004 12/1948 Larkin 214-6 2,634,852 4/1953 Clauss 214-6 X 2,639,049 5/1953 Kinzelman et al. 2146 X 2,918,852 12/1959 Bucoicone 214-8 X 2,957,691 lO/1960 Williams 27188 2,967,630 1/1961 Parker 214-6 3,111,233 11/1963 Raynor 214-6 3,126,657 3/1964 Hajos 2l46 X FOREIGN PATENTS 422,854 6/ 1947 Italy.

GERALD M. FORLENZA, Primary Examiner. ROBERT J. SPAR, Assistant Examiner.

US. Cl. X.R. 27188 

